Centrifugal separator having lining of elastomer material



Dec. 12, 1961 P. STEINACKER 3,012,710

CENTRIFUGAL SEPARATOR HAVING LINING OF ELASTOMEYR MATERIAL Filed on. 27.1958 20 1 I I I I I l I I I -/a I I I l I I I l8 1 I I O I 2 l l I I I I26 I I l l /0 I 3 9 l /4 I la/ 5 INVENTOR PETER STE/NACKER ATTORNEYSPatented Dec. 12, 1961 This invention relates to centrifugal separatorsand more particularly to such separators lined with elastomer materialto render the apparatus suitable for use in treating corrosivematerials. The principal object of the invention is to provide a liningcharacterized in that there are no discontinuities along the lining.Such construction produces no areas within the bowl which aresusceptible to attack by corrosive material.

In order to prevent damage by corrosion in the centrifugal treatment ofcorrosive liquids, it has been customary for a long time to line theparts of the bowl, which come into contact with the centrifuge liquidand generally consist of forged steel with a stainless steel plate.Stainless steel, however, is also not always resistant to corrosion,particularly not in the presence of chlorine ions. For such centrifugeliquids, rubberized bowls are generally employed. .The rubberizingconsists of several thin layers which are bonded one over the other ontothe metal parts and thereupon Vulcanized at suitable temperature.

With the centrifuge bowls known up to the present time, lined withrubber on other elastic material, disadvantages are encountered howeverwhich are avoided by the bowl inaccordance' with the invention.

It is known that the bowl bottom part and the bowl inserts, for instancethe distributor, must be locked together so as to prevent relativerotation. For this purpose, there are generally provided on one of thesebowl parts locking lugs which engage in corresponding recesses of theother part of the bowl. In the case of one known lining, both these lugsand the surfaces adjoining the recesses are covered with a protectivecovering. Aside from the difiiculties caused in the lining of suchparts, the cooperation of rubberized "parts does not always afiorddependable assurance against rotation. The large amount of frictionbetween the rubberized parts is also detrimental in connection with theassembling and taking apart of the bowl. In order to maintain the playof the anti-rotation device as low as possible, the lugs must fit Wellin the recesses. Upon assembling these bowls, bulgings of the rubberlayers can prevent a firm seat of the inserts on all sides in the bottompart of the bowl while upon disassembly the lining'can be torn anddamaged, particularly at the edges of ribs and lugs. In order tocircumvent this drawback, an attempt has been made to make out ofresistant material the ribs and lugs firmly connected with the parts andleave them unco-v ered. This, however, means an interruption of theprotective layer and such interruptions are always the starting pointsfor the peeling of the protective covering from the metal. The corrosiveliquid can therefore pass behind this layer, form bubbles under theaction of the centrifugal force, and destroy the metal.

In addition to the locking device, the lining of the distributor alsoaffords considerable difiiculties in the case of disk bowls. In general,the inner surface of the distributor which limits the inlet space of thebowl is equipped with driving blades in order to impart the speed ofrotation of the bowl to the incoming material to be centrifuged. Thenarrow distributor neck makes the covering of the driving ribs with theprotective covering very diflicult so that one is limited to coveringthe cutting into the lining of the. bowl hub when the upper outerdistributor neck and the distributor base. The fact that the entiredistributor must be replaced by a new one when the driving ribs aredestroyed by corrosion is particularly disadvantageous.

Anothter disadvantage of the centrifuge bowls previously lined withelastic material is that upon assembling the bowl, the unlined drivingblades may damage the lining of the bowl vhub and upon tightening of theclosure ring cut into said lining. Furthermore, when the bowl cover isplaced on, a metal guide is not present in the case of the previouslyknown models so that lined parts can be damaged by the edges ofuncovered parts.

All of these disadvantages are eliminated with the bowl in accordancewith the invention. One essential feature of the invention is that thelining of the bowl parts is not interrupted. The locking pieces arefirmly connected with rings which are bonded, vulcanized, or in someother manner fastened to the continuous lining. Locking members andrings consist of non-corrosive material.

' Another feature of the invention is that in the case of disk bowls,the driving ribs of the distributor neck are combined in the form'of areplaceable unit which is detachably connected (to the distributor, Inthe case of chamber bowls, the blade insert as it is constitutes anindependent part. In order to prevent the blade insert and lower partsof the bowl are pressed together, there is provided a protective platewhich-is adapted to the shape of the bowl hub. In order, furthermore, toprevent the damaging of the lining of the hub upon insertion of thedistributor or of the blade insert, the outer upper edge of this liningis framed with metal. Due to the fact that in the case of disk bowls,the blade insert is detachably connected as an independent unit to thedistributor, it is merely necessary, after a corresponding time ofoperation, to replace this insert only by another one. However, it canalso be made of non-corrosive material. A further characteristic of the,bowl in accordance with the invention is the metallic guiding of thebowl cover when it isplaced on. By this guide, a tilting of' the coverand thusdamage to its lining is made impossible. Too great a pressing ofthe linings of the bowl cover and the bottom part of the bowl isprevented --by' the metallic resting of both parts during the tighteningof the closure ring. I

The invention will be further described with reference to theaccompanying drawing wherein of the invention is depicted. 1

1 According to the invention, the bowl and bowl cover are each at leastpartially lined with'elastomer material suc-has rubber-:or plastic, andhave radially extending mating surfaces ,for closely fitting'the bowlcover on thebowl. The mating surfaces each have a radiallyextendingrrecess which extends part way along the mating surfaces frominside the bowlyandithe bowl lining'eio.

recesses and theclosure means which secures the bowland bowl covertogether, presses the bowl and bowl cover together, so that the matingsurfaces outwardly of the recesses engage each other in metal to-metalengagement.

compressed providing a hermetic seal.

The insert for guiding material centrifuged within the bowl isdetachably mounted in the bowl for rotationtherewith. The'detachablemounting means comprises a base member secured to the bowl and a basemember secured to th'einsert and the base member secured to "anembodiment Thus, the bowl and bowl cover are tightly secured together,and the lining parts in the recesses are the bowl is secured to the bowlby bonding to the clastomer bowl lining. The radially extending drivingblades, which extend to adjacent an inwardly disposed elastomer linedsurface of the bowl and terminate in edges disposed adjacent theelastomer lined surface, are advantageously provided with protectingplates which extend axially of the bowl and are secured to the edges ofthe driving blades. Thus, engagement of the blade edges and theelastomer of the lined bowl surface is prevented so the lining is notcut by the blade edges.

Referring to the drawing, there is there shown a disk separator. Theseparator consists of a bottom part 1 and a cover 2, which are heldtogether by means of a closure ring 3. On the lining 4 of the bottompart 1 of the bowl, there is bonded or vulcanized a base member or ring6 consisting of non-corrosive material and having secured thereto thebare locking lugs 5. In this way an interruption of the lining 4 isprevented. The bowl insert includes the disk set 16, distributor 13 anddriving blades 7. The driving blades 7 are connected rigidly together toform a single replaceable unit by means of a sleeve 8 and an insert basemember or ring 9. The ring 9 is provided with bare recesses 10 toreceive the locking lugs 5. In order to prevent the ribs 7 digging intothe lining 4 of the bowl hub 11, an axially extending protective plate12 adapted to the shape of the bowl hub 11 is secured to the edges 26 ofthe driving blades 7 along the bottom third thereof. The distributor 13is provided, below the distributor foot 14, with firmly connecteddriving blades 15. The distributor 13 with foot 14 and blades 15 islined on all sides with a protective layer 16' consisting of elastomermaterial. The outer edge of the lining 4 terminating on the shaft of thebowl hub 11 is metallically framed by means of a profile ring 17.

The lining 18 of the bowl cover 2 is clamped fast at its upper end bymeans of a ring 19. It may be advisable to insert a special gasket 20between the ring 19 and the lining 18.

The blade unit consisting of the driving blades 7, the sleeve 8 and thering 9 is inserted in the distributor 13 outside the bowl. The bladeunit and the distributor are detachably connected with each otherbyscrewing the distributor head 21 onto the sleeve 8. The unit which isthus produced is inserted into the bottom part 1 of the bowl and turneduntil the locking lugs engage in the recesses of the blade unit. In thisconnection, the ring 9 is guided along the outer surface of thecylindrical part of the ring 6. The edges of the driving blades 7therefore do not come into contact with the lining of the bowl hub 11.By the cooperation of the unlined lugs with the unlined recesses, a goodseat for the insert, as well as good assurance against rotation, areassured. Likewise, no friction of rubberized parts against each othercan occur since'the distributor foot 14 and the driving blades come torest on the bottom of the bowl only after the lugs 5 have engaged in therecesses 10.

The ring 19 connected with the bowl cover 2 is guided on the cylindricalouter surface of the distributor head 21 when the bowl cover is placedon. In this way a tilting of the bowl cover and thus damage to therubberized inner surface are avoided. The bowl and bowl cover areprovided respectively with radially extending mating surfaces 22a and 22and disposed along these surfaces, respectively, are recesses 27 and 28.The lining of the bowl and bowl cover extend into these recesses and thelinings are of such thickness that the abutting portions thereof arecompressed by each other and provide a seal. Due to the fact that thebottom part 1 of the bowl and the bowl cover 2 are metallically seatedat radially extending mating surfaces 22 and 22a, when screwed togetherby means of the closure ring 3, the surface pressure between the liningsis limited. The disk bowl shown in the embodiment is equipped on theperiphery of the bowl with nozzles 23 which make an interruption of thelining necessary at these points. These interruptions are howeverinsignificant since the lining is not raised from the metal under thepressure of the centrifugal force but rather pressed firmly against themetallic face. The invention is not limited to disk bowls, but can alsobe employed advantageously in connection with bowls of any other type.Of course, it is also possible to provide the locking lugs on the wingunit and the corresponding recesses in a ring arranged in the bottompart of the bowl.

The insert is secured in the bowl for rotation therewith by thedetaohable mounting provided by engagement of the lugs 5 in recesses 10and by engagement of insert elements with the bowl and bowl cover. Thedistributor foot 14 extends radially outwardly from the insert hub andengages the bowl at its outer extremity, and the top disc 30 of the discset 16 extends radially outwardly and engages the bowl cover. Thedistributor foot 14 and the top disc 30 press against the bowl and bowlcover and aid in suitably securing the insert 'in the bowl.

I claim:

1. In a centrifugal separator having a rotatably mounted bowl at leastpartially lined with a protective layer of elastomer material, a bowlcover, closure means for fixedly securing the bowl cover to the bowl, aremovable insert for guiding material centrifuged within the bowl, lugmeans secured to the base of said bowl, and correspondingrecesses insaid insert for receiving said lugs to connect said bowl and insert forrotation together, the improvement which comprises said lug means beingmounted on a separate base member bonded to the surface of saidelastomer material layer leaving said layer of elastomer materialuninterrupted at the area of said lug means.

2. Improvement according to claim 1 in which said insert includes aradially extending driving blade terminating in an edge disposedadjacent said protective layer of elastomer material, and including anaxially extending protective plate secured to said edge of said drivingblade, whereby engagement of the blade edge and the layer of elastomermaterial is prevented.

3. Improvement according to claim 1 in which the bowl and bowl cover areeach at least partially lined with a protective layer of elastomermaterial and in which said bowl and bowl cover have radially extendingmating surfaces for closely fitting the bowl cover on the bowl, themating surfaces each having a radially extending recess extending partway along the surfaces from inside of the separator, the protectivelayer lining the bowl extending into the recess of the bowl matingsurface and the protective layer lining the bowl cover extending intothe recess of the cover mating surface, the normal thickness of theprotective layers disposed in the recesses being greater than the depthof the recesses, said closure means securing the bowl and cover togetherwith said mating surfaces outwardly of said recesses in matingmetal-to-metal engagernent whereby the bowl and bowl cover are tightlyand hermetically sealed together without injury to the protectivelayers.

References Cited in the file of this patent UNITED STATES PATENTS819,765 Kiel May 8, 1906 1,402,591 Gallus Jan. 3, 1922 1,748,138 McBrideFeb. 25, 1930 2,017,734 Sandstrom Oct. 15, 1935 2,272,675 Knudsen Feb.10, 1942 2,592,419 Harper et al Apr. 8, 1952 2,613,011 Foreshaw-SmithOct. 7, 1952 2,645,415 Strezynski July 14, 1953 2,661,150 Abbott Dec. 1,1953 2,779,469 Harris Jan. 29, 1957 2,787,374 Krebs Apr. 2, 19572,816,658 Braun et a1. Dec. 17, '1957

